Vials are frequently used in medical practice. Usually, vials consist of a container filled with a medicinal fluid and sealed with a seal which can be pierced with a hypodermic needle. The vial is often also provided with a protective cap which needs to be removed before use. In the process of producing these vials, there is a considerable chance of medicinal fluid ending up on the outside of the vial. Therefore, after filling and sealing, the vials are rinsed in order to remove this fluid. However, it is known from practice that the outside of a vial is not always clean, i.e. free from contamination with an active substance. In that case, rinsing has not led to complete removal, and still traces of the active substance have remained.
Often, the fact that traces of an active substance remain does not constitute a problem, but in certain cases, such as for example in the case of cytostatics and antibiotics, this is different. For instance, it is known that cytostatics can absorb on glass. This may then cause hospital and pharmacy employees, in dealing with such vials, to undesirably get in contact with these possibly highly toxic substances. In the case of antibiotics, contamination on the outside is undesirable, because this may lead to faster resistance of micro-organisms against the antibiotics concerned when these micro-organisms get in contact with the vial, or when the antibiotics concerned get in contact with micro-organisms carried by hospital and pharmacy employees.